Assessment of a rapid diagnostic test to exclude bacteraemia and effect on clinical decision-making for antimicrobial therapy.

Unnecessary antimicrobial treatment promotes the emergence of resistance. Early confirmation that a blood culture is negative could shorten antibiotic courses. The Cognitor Minus test, performed on blood culture samples after 12 hours incubation has a negative predictive value (NPV) of 99.5%. The aim of this study was to determine if earlier confirmation of negative blood culture result would shorten antibiotic treatment. Paired blood cultures were taken in the Critical Care Unit at a teaching hospital. The Cognitor Minus test was performed on one set >12 hours incubation but results kept blind. Clinicians were asked after 24 and 48 hours whether a result excluding bacteraemia or fungaemia would affect decisions to continue or stop antimicrobial treatment. Over 6 months, 125 patients were enrolled. The median time from start of incubation to Cognitor Minus test was 27.1 hours. When compared to 5 day blood culture results from both the control and test samples, Cognitor Minus gave NPVs of 99% and 100% respectively. Test results would have reduced antibiotic treatment in 14% (17/119) of patients at 24 and 48 hours (24% at either time) compared with routine blood culture. The availability of rapid tests to exclude bacteraemia may be of benefit in antimicrobial stewardship.

Changes in dental plaque following hospitalisation in a critical care unit: an observational study.

INTRODUCTION: Previous research has suggested that deterioration in oral health can occur following hospitalisation. The impact of such deterioration could increase the risk of oral disease, reduce quality of life and increase the potential for healthcare-associated infections (HCAI) such as healthcare-associated pneumonia (HAP). However, the strength of the evidence is limited by, amongst other factors, the few observational studies published that assess oral health longitudinally. In view of the microbiological component of oral diseases and HCAIs, the objective of this study was to investigate the microbiological changes in dental plaque following hospitalisation in a Critical Care Unit (CCU): (1) total number of cultivable bacteria and (2) presence and changes in specific HAP pathogens. METHODS: We conducted a prospective, longitudinal observational study in the CCU of University College Hospital, London. Study participants were recruited within 24 hours of admission. Dental plaque samples were collected from up to six sites per patient. The primary outcome was microbiological change from baseline to seven days with additional analysis for participants still present at day 14. RESULTS: 50 patients were recruited with 36 available for review at one week, with early discharge accounting for much of the loss to follow-up. The median total viable count of the plaque microbiota at baseline was 4.40 × 105 cfu/ml and increased at week one to 3.44 × 106 cfu/ml. The total viable microbe counts increased by a median of 2.26 × 106 cfu/ml from baseline to week one (95% CI: 3.19 × 106, 1.24 × 107) and this was statistically significant (P < 0.01). Specific HAP bacteria were detected in 26% of participants sampled, although accounted for a relatively low proportion of the total viable bacteria. CONCLUSION: Total bacterial count of dental plaque increases during hospitalisation in CCU. This finding, together with the colonisation of dental plaque by HAP bacteria strengthens the evidence for a deterioration in oral health in CCU and a risk factor for negative health and quality of life outcomes.

The impact of hospitalization on dental plaque accumulation: an observational study.

AIM: To investigate the effect of hospitalization on oral health as assessed by dental plaque. MATERIALS AND METHODS: Observational study in a critical care unit (CCU). Participants were recruited within 24 h of admission. Dental plaque amount was assessed at baseline, 1 and 2 weeks using the Debris index-soft deposits (Greene & Vermillion 1960). RESULTS: Fifty participants were recruited with 36 available for outcome assessment at 1 week and 10 at 2 weeks. The principal reason for losses was early discharge with no evidence of a difference between patients present only at baseline and those present at 1 week. The median value for dental plaque at baseline was 4 (95% CI: 4, 6). The median dental plaque increase from baseline to week 1 was 1.5 (95% CI: -1, 4), and this was statistically significant (p = 0.04). The median increase from week 1 to week 2 was 1.0 (95% CI -8, 6) and not statistically significant (p = 0.68). CONCLUSIONS: Oral health as assessed by dental plaque deteriorates following hospitalization in CCU. Such change could lead to impairment of quality of life and well-being as well as to increasing the risk of important healthcare-associated infections such as nosocomial pneumonia.